The “Saturday Night Live” standout stood out in the female “Ghostbusters” reboot, owning every scene she was in and eclipsing the better-known likes of Melissa McCarthy and Kristen Wiig. But she was a relatively minor component in that ensemble. She’s got much more prominence in “The Spy Who Dumped Me” as Morgan, the boundary-breaking best buddy of the dumpee of the title, Audrey, played by Mila Kunis.

Kunis has the straight-man, er, straight-woman role in the pairing, a cautious 30-year-old in a dead-end cashier’s job at an Los Angeles organic supermarket that bears a sneaking resemblance to Trader Joe’s with dress code to match (“I wear a Hawaiian shirt to work”).

At the start, she’s just been ditched (By text! Grrr!) by her boyfriend, a way-handsome man of mystery (Justin Theroux) seen trading gunfire and body blows with assorted assassins in Vilnius, Lithuania. When he returns to L.A., bringing his pursuers with him, they’re soon pursuing Audrey and Morgan across exotic European locations. How these two minimum-wage BFFs can afford the overseas airfare is one of the unexplained puzzles of the picture.

Over there, they fall in with another suave spy (Sam Heughan), who seems like a nice guy, but, hmm, maybe is not. More mystery.

“Spy” is wildly uneven, with director and co-writer Susanna Fogel (David Iserson shares screenplay credit) loading it up with lots of the usual spy-thriller action: wild car chases, shootouts, explosions, etc. — accompanied by a lot of panicked screaming on the part of the women trying to survive the rough stuff.

However, in the midst of all that, again and again, McKinnon rises above the hoopla with moments of sheer near genius. An instant of dexterous physical comedy in which she locks a car door with a remote switch is more genuinely jaw-dropping than all of the movie’s elaborately choreographed gunbattles.

Introduced to the chilly spy chief played by Gillian Anderson, she declares with a sly, awed smile, “You’re the boss? And yet you have not sacrificed an ounce of femininity.” That, she marvels, makes Anderson’s character “the Beyoncé of government.” That’s McKinnon at her singular best.

The two stars play off each other very well, with Kunis displaying a genuine gift for comedy. A scene in which, under torture, they blubber out deeply held secrets — Audrey: “She has sex dreams about Minions”; Morgan: “Just the one Minion with the one eye” — is a stitch.

Soren Andersen: asoren7575@yahoo.com. Soren Andersen has been writing about movies since he was in high school, back when dinosaurs roamed the Earth. He has written for papers in Southern California and Washington, and was the staff critic at the News Tribune in Tacoma for 25 years.